W-Shaped π-Extended Double Undecabenzo[7]helicene.

A chiral W-shaped fully π-extended double [7]helicene (ED7H) has been synthesized and fully characterized. It displays fluorescence emission (λem = 636 nm) with a quantum yield (Φf) of 0.10. In comparison to its X-shaped and monomict π-extended [7]helicene analogues, enantiopure W-shaped ED7H exhibited superior chiral optical characteristics, including distinct circular dichroism signals from 400 to 650 nm, a good dissymmetric emission factor |glum| of 4 × 10-3, and a circularly polarized luminescence brightness value BCPL of 42 M-1 cm-1.

Synthesis and Preclinical Evaluation of Novel 99mTc-Labeled FAPI-46 Derivatives with Significant Tumor Uptake and Improved Tumor-to-Nontarget Ratios.

Fibroblast activation protein (FAP), which is expressed on the cell membranes of fibroblasts in most solid tumors, has become an important target for tumor diagnosis and treatment. However, previously reported 99mTc-labeled FAPI-04 complexes have high blood uptake, limiting their use in the clinic. In this work, six 99mTc-labeled FAPI-46 derivatives with different linkers (different amino acids, peptides, or polyethylene glycol) were prepared and evaluated. They had good in vitro stability, hydrophilicity, and good specificity for FAP. The biodistribution and MicroSPECT images revealed that they all had high specific tumor uptake for FAP, and their blood uptake was significantly decreased. Among them, [99mTc]Tc-6-1 exhibited the highest target-to-nontarget ratios (tumor/blood: 6.06 ± 1.19; tumor/muscle: 10.26 ± 0.44) and good tumor uptake (16.15 ± 0.83%ID/g), which also had significantly high affinity for FAP, good in vivo stability, and safety. Therefore, [99mTc]Tc-6-1 holds great potential as a promising molecular tracer for FAP tumor imaging.

A π-Extended Pentadecabenzo[9]Helicene.

A novel chiral nanographene (i.e. EP9H) with a pentadecabenzo[9]helicene core fragment has been synthesized and fully characterized. Single-crystal X-ray diffraction unambiguously confirms the helical structure. The fluorescence emission of EP9H is located in the near infrared region (λem =684 nm) with a medium quantum yield (0.10) for helicene derivatives. Cyclic voltammetry reveals its seven quasi-reversible redox states from -2 to +5. Furthermore, enantiopure EP9H displays distinct CD signals in a broad spectral range from 300 to 700 nm. Notably, compared to the reported small organic molecules, EP9H displays an outstanding |glum | value of 4.50×10-2 and BCPL as 304 M-1 cm-1 .

Highly Sensitive Uric Acid Detection Based on a Graphene Chemoresistor and Magnetic Beads.

In this study, we developed a low-cost, reusable, and highly sensitive analytical platform for the detection of the human metabolite uric acid (UA). This novel analysis platform combines the graphene chemoresistor detection technique with a magnetic bead (MB) system. The heterojunction (single-layer graphene and HfO2 thin-film material) of our graphene-based biosensor worked as a transducer to detect the pH change caused by the specific catalytic reaction between UA and uricase, and hence acquires a UA concentration. Immobilization of uricase on MBs can decouple the functionalization steps from the sensor surface, which allows the sensor to be reusable. Our microsensor platform exhibits a relatively lower detection limit (1 µM), high sensitivity (5.6 mV/decade), a linear range (from 1 µM to 1000 µM), and excellent linearity (R2 = 0.9945). In addition, interference assay and repeatability tests were conducted, and the result suggests that our method is highly stable and not affected by common interfering substances (glucose and urea). The integration of this high-performance and compact biosensor device can create a point-of-care diagnosis system with reduced cost, test time, and reagent volume.